1. Field of the Invention
The present invention relates to an image pickup device, an image blur correcting method, and a program that can efficiently process an image blur caused by a vibration or the like.
2. Description of the Related Art
An image picked up by an image pickup device such as a digital camera or the like may have a blur, or a so-called hand movement blur, of a subject image due to for example the shaking of the hand of a user holding the body of a camera at a time of image pickup. Therefore the digital camera incorporates a correcting function for correcting the blur of the subject image (hereinafter referred to as an “image blur”) appearing in the picked-up image due to a vibration applied to the body of the camera, including the hand movement of the user.
An optical image blur correction process and an electronic image blur correction process have been known as image blur correction process, and the image blur correction process is realized by cancelling an image blur by these processes.
The optical image blur correction process detects a vibration applied to the body of a camera by an angular acceleration sensor or the like, rotates a prism provided inside an image pickup optical system for forming a subject image in accordance with a result of the detection, and thus changes the direction of an optical axis of the image pickup optical system, whereby an image formed on the light receiving surface of an image pickup element is moved to correct an image blur. The electronic image blur correction corrects an image blur by performing image processing on the picked-up image.
An existing image pickup device using one of the optical image blur correction process and the electronic image blur correction process to perform an image blur correction process can secure a sufficient correction margin to perform correction for an image blur of relatively small amplitude of detected image blur signals. However, for an image blur of large amplitude occurring when image pickup is performed from a moving body such as a car, for example, the existing image pickup device may not secure a sufficient correction margin, and may not perform image blur correction efficiently.
In order to perform a correction process for such an image blur of large amplitude, the existing image pickup device secures a correction margin as follows. A correction margin is secured by widening a correction angle when optical image blur correction is performed, whereas a correction margin is secured by widening a correction surplus region when electronic image blur correction is performed.
However, in the case of optical image blur correction, by widening the correction angle, a lens and an actuator are increased in size, and the image pickup device itself is increased in weight with the increase in size of the lens and the actuator. Further, a large amount of power is consumed for shift driving of the lens increased in size, and various problems such for example as degradation in optical performance due to greatly shaking the lens occur.
In the case of electronic image blur correction, widening the correction surplus region reduces a performance region, and thus degrades the image. In addition, a long image updating cycle degrades correction performance.
Techniques of Japanese Patent Laid-Open No. Hei 11-146260 are proposed for these problems. The techniques of Japanese Patent Laid-Open No. Hei 11-146260 are to achieve blur correction without degradation in image quality by using optical blur correction and electronic blur correction jointly.